Two pipes fill a storage tank in 9 hours. If the larger pipe fills the tank three times as fast as the smaller one, how long would it take the larger pipe to fill the tank alone?

Question

In terms of your variable, what fraction of the tank is filled in 1 h by the larger pipe alone? By the smaller pipe alone?

Please explain step-by-step.

Answer 1

Let t = time required by the larger pipe alone
then
3t = time required by the smaller pipe alone

Let the completed job = 1; (a full tank)

Each pipe will fill a fraction of the tank, the two fractions add up to 1.

9/t + 9/3t = 1
27 + 9 = 3t
36 = 3t
12 = t
Large pipe :12 hours
Small pipe: 36 hours